Transcript PRES_EPA Stormwater ppt_Rachel Herbert (final)

EPA’s Stormwater Rulemaking:
How Potential Changes in the NPDES Stormwater
Regulations Could Impact the Design of
Stormwater Controls
Rachel Herbert
USEPA/OW/OWM/WPD
for
AASHTO Subcommittee on Design Meeting
Purpose of Today’s Discussion
 Construction & Development Effluent Limitation
Guidelines
www.epa.gov/guide/construction
 New Stormwater Regulations
www.epa.gov/npdes/stormwater/rulemaking
Overview of Construction & Development
Effluent Limitation Guideline (C&D ELG)
 General Overview of Requirements
 Erosion & Sedimentation Requirements
 Sampling Requirements
 Other Requirements
General C&D ELG Requirements
 EPA promulgated new regulations for construction and development
(C&D) sites on December 1, 2009. New rule requires all construction
sites subject to permits to implement erosion and sediment controls
and pollution prevention measures
 Phase-in requirement for sites to sample stormwater discharges and
comply with a numeric effluent limitation (NEL) of 280
nephelometric turbidity units (NTU).
 Beginning August 1, 2011 sites disturbing 20+ acres at once
 Beginning February 2, 2014 sites disturbing 10 acres at once
 Requirements must be incorporated into state permits (general or
individual) whenever permits are re-issued
 EPA intends to issue a new CGP in June 2011
Erosion and Sedimentation Requirements
 Control stormwater volume and velocity within
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the site to minimize soil erosion;
Control stormwater discharges to minimize
erosion at outlets and downstream channel
and streambank erosion;
Minimize the amount of soil exposed during
construction activity;
Minimize the disturbance of steep slopes;
Design, install and maintain erosion and sediment controls
considering factors such as precipitation and soil characteristics;
Provide and maintain natural buffers around surface waters, direct
stormwater to vegetated areas to increase sediment removal and
maximize stormwater infiltration, unless infeasible; and
Minimize soil compaction and, unless infeasible, preserve topsoil.
Sampling Requirements
 280 NTU Limitation does not apply on days with
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precipitation exceeds the local 2-year, 24-hour
storm event
Monitoring frequency is up to the permitting
authority, but EPA recommends at least 3 grab
samples per day at each discharge point
EPA has not specified any analytical methods, but
envisions that use of a properly calibrated field
turbidity meter is adequate
For linear projects, permitting authority can
consider representative sampling instead of
sampling at each discharge point
Even if permitting authority allows representative
sampling, all discharge points are still subject to
compliance with effluent limitation
Permitting authority will specify data reporting
requirements
Other Requirements
 Soil Stabilization & Dewatering Requirements
 Initiate stabilization of disturbed areas immediately
whenever any clearing, grading, excavating or other earth
disturbing activities have permanently ceased,
 when earth disturbing activities have temporarily ceased
and will not resume for a period exceeding 14 calendar
days.
 Where vegetative stabilization is infeasible, alternative
stabilization measures must be employed.
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 Pollution Prevention Requirements
 Prohibited Discharges
Overview of New Rulemaking
 Background on the Federal Stormwater
Program
 Stormwater Challenges
 The National Research Council (NRC)
Report
 EPA has initiated a rulemaking to
improve its stormwater program.
 Stormwater Rulemaking Schedule
 Preliminary Considerations for
Rulemaking
Federal Stormwater Regulations
Phase I
Phase II
Year Finalized 1990
1999
Regulated
Entities
Medium & large MS4s
Small MS4s in an
“urbanized area” (UA)
10 categories of industrial
operations
Additional designated
MS4s outside of UAs
Active construction sites of 5
acres or more
Active construction
sites disturbing
between 1 and 5 acres
Federal Stormwater Regulations (cont’d)
Phase I
MS4
Stormwater
Management
Program
(SWMP)
Requirements
MS4 must develop and
implement a SWMP to:
• find and eliminate illicit
discharges
• control discharges from
its system by addressing
discharges from active
construction sites, new
development and
redevelopment, and
industrial activities
Phase II
MS4 must develop and
implement a SWMP that
includes 6 minimum
measures:
• Public education & outreach
• Public participation/
involvement
• Illicit discharge detection &
elimination
• Construction site runoff control
• Post-Construction site runoff
control
• Pollution prevention/ good
housekeeping
Federal Stormwater Regulations (cont’d)
Phase I
Stormwater
Pollution
Prevention Plan
(SWPPP)
Requirements
Construction & industrial
stormwater dischargers
must develop and
implement a SWPPP
Phase II
N/A
Stormwater Challenges
Much progress has been
made; however, significant
challenges remain to protect
waterbodies from impact of
stormwater discharges
• Urban stormwater is the primary source of
water quality impairment:
 13% of all rivers and streams
 18% of all lakes
 32% of all estuaries
The National Research Council (NRC) Report
 In 2006 EPA commissioned the National Research Council (NRC) to
study EPA’s stormwater program
 In October 2008 NRC released Urban Stormwater Management in
the United States, available at: www.epa.gov/npdes/stormwater
 Key Findings
 Current approach is unlikely to produce an accurate picture of
the problem and unlikely to adequately control stormwater’s
contribution to waterbody impairment
 Requirements leave a great deal of discretion to dischargers to
set their own standards and ensure compliance, which results in
inconsistency across the nation
 Poor accountability and uncertain effectiveness
Key Recommendations in the NRC Report
 “A straightforward way to regulate stormwater
contributions to waterbody impairment would be
to use flow or a surrogate, like impervious cover,
as a measure of stormwater loading ….”
 “Efforts to reduce stormwater flow will
automatically achieve reductions in pollutant
loading. Moreover, flow is itself responsible for
additional erosion and sedimentation that
adversely impacts surface water quality.”
US Department of
Transportation
Headquarters
Washington, DC
 “Stormwater control measures that harvest,
infiltrate, and evapotranspirate stormwater are
critical to reducing the volume and pollutant
loading of small storms.”
Turkeyville, MI
Rest Area 722
Stormwater Rulemaking Schedule
Primary impetus: to protect waterbodies
from the stormwater impact of urbanization
Completed Activities:
 October 30, 2009: Federal Register (FR) Notice announcing EPA’s
intent to distribute questionnaires (Information Collection Request
(ICR) seeking data to inform the rulemaking from three groups:
 Owners, operators, developers, and contractors of developed
sites
 Owners of Municipal Separate Storm Sewer Systems (MS4s)
 States and territories
 January – March 2010: Listening Sessions input on preliminary
rulemaking considerations (FR Notice published Dec. 28, 2009)
 May 2010: EPA published a final FR ICR Notice
Stormwater Rulemaking Schedule (Cont’d)
Upcoming Activities:
 Summer 2010: EPA expects to distribute the questionnaires
 Late 2011: EPA expects to propose a rule to be published in
the FR for public comment
 Late 2012: EPA expects to take final action
Preliminary Considerations for Rulemaking
1.
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5.
Expand the universe of regulated discharges beyond
urbanized area
Establish substantive post-construction requirements for
new and redevelopment
Develop a single set of consistent requirements for all
MS4s, in place of existing “Phase I” and “Phase II” rules
Address stormwater discharges from existing development
through retrofitting
Consider additional requirements to further reduce
stormwater impacts in the Chesapeake Bay
NOTE: No decisions have been made on any
of the items discussed from this slide forward.
1. Expand the universe of regulated
discharges beyond urbanized area:
Depiction of Current MS4 Roadway Regulation
Area C
(regulated MS4)
Area B
(not a regulated MS4)
Key
Area A
(regulated MS4)
Regulated MS4 area
NOTE: Disturbances of ≥ 1 acre are required to comply with NPDES
construction requirements, even If outside the urbanized area.
1. Expand the universe of regulated discharges
beyond urbanized area
• What is the best way to expand the universe of regulated discharges
beyond Urbanized Area?
• Is there an appropriate boundary for permit coverage if not based
on the current definition of Urbanized Area?
• What criteria could be used to identify areas?
• Should States decide the areas to include?
2. Establish substantive post-construction
requirements for new and redevelopment
 Develop a standard that promotes sustainable practices
that mimic natural processes to infiltrate and recharge,
evapotranspire, and/or harvest and reuse precipitation.
 Should there be a national requirement for on-site
stormwater controls such that post development
hydrology must mimic pre-development hydrology on a
site-specific basis?
 Options for meeting the requirement could be: on-site
retention of specific sized storm, limits on amount of
effective impervious area, use of site-specific calculators to
determine predevelopment hydrology, and/or use of
regional standards to reflect local circumstances.
 Options if standard could not be met: off-site mitigation,
payment in lieu, others?
 Should the standards be different for new development
vs. redevelopment?
3. Develop a single set of consistent requirements for
all regulated MS4s
Many Phase I & II MS4s address issues that are similar,
but the regulatory requirements are different.
 Should DOTs have different requirements than traditional
MS4s?
 What requirements should EPA apply to DOTs? Should EPA
apply all of the 6 minimum measures to DOTs? Are there
other measures that would achieve better water quality, like
more emphasis on source control?
 Phase I MS4s are required to implement a program to control
discharges from industrial facilities. Should this requirement
be extended to all MS4s?
4. Addressing stormwater discharges from existing
development
Stormwater discharges from developed areas are
significant contributors to water quality impairments;
some MS4 permits require retrofit practices that
infiltrate or retain stormwater.
 Should EPA consider retrofit requirements, such
as:
 Development of a retrofit plan?
 Implementation of a retrofit plan?
 Should any requirements apply only to large
MS4s?
 Should any requirements apply only to water
quality impaired waters?
5. Consider additional requirements to further
reduce stormwater impacts in the Chesapeake Bay
 What additional requirements should EPA consider to protect
the Chesapeake Bay?
 Buffer requirements?
 Additional requirements on active construction?
 Further extending area of coverage?
 Should these provisions be applied to other sensitive areas?
Contact
Rachel Herbert
[email protected]
202-564-2649